It probably did. Just from a perspective of idle layman speculation, Erdős probably had a self-medicated, undiagnosed form of adult ADD. He routinely used amphetamines and methylphenidate (i.e. the two most widely-prescribed ADD drugs) and when he stopped using them for a month, he was incapable of focusing long enough to do his work. From the research I've done, he managed to maintain prescriptions to his stimulants based on a "depression" diagnosis, which is also consistent (adult ADD often manifests as depression).